Many domestic and commercial water usage applications may require relatively high pressures, which may be beyond the capacity of residential and/or municipal water distribution and supply systems. For example, heavy duty cleaning applications may benefit from increased spraying pressure that is greater than the pressure available for common residential and/or municipal water distribution and supply systems. In some situations, various nozzles may be utilized to constrict the flow of the water to provide an increase in the pressure of the resultant water stream. However, many tasks may benefit from even greater pressures than can be achieved with common pressure nozzles that may be attached to a hose. In such circumstances pressure washers may be utilized, in which a power driven pump may be employed to increase the pressure significantly above pressures that are readily achievable using hose attachments. Such elevated pressures may greatly increase the efficiency and/or effectiveness of some cleaning and spraying tasks.
While the increase in pressure that may be provided by a pressure washer may be useful for many applications, in many circumstances the demand for the pressurized water may be intermittent, or required on a stop and go basis. Often the intermittent demand for the pressurized water is satisfied by various valves or flow restrictors that may be located in the nozzle of the pressure washer, or at some location between the pressure pump of the pressure washer and the nozzle. While valves of this nature may satisfy the intermittent demand for the pressurized water, when the valve is closed the pump may be continue trying to pump against the closed valve, which may impart stress on the pump and/or the prime mover. The stress imparted on the pump and/or the prime mover working against the closed valve may, in some situations, accelerate wear on the pump or prime mover, or otherwise decrease the useful life cycle of the components.